Next time the nurse tells you to hop up on the exam table so they can take your blood pressure, don’t. “When you’re sitting like that with your feet dangling, you’re almost between sitting and standing. This can affect your reading because your blood pressure is different when you’re standing versus lying down,” says Nieca Goldberg, MD, medical director of the Joan H. Tisch Center for Women’s Health at NYU Langone Medical Center in New York City. The proper position is seated in a chair with your back flat against the chair back and your feet flat on the floor (no crossing allowed!). Any good doctor should accept your request to sit in a chair instead of atop a crinkly exam table, she says.

How you hold your arm

If your arm isn’t supported, blood pressure readings can get messed up. “Your arm should be flat on a table or supported by the person taking your pressure, it shouldn’t just be hanging in the air,” says Dr. Goldberg. If your arm is too high or low, it can affect how hard your heart has to pump to keep blood flowing, which then affects your blood pressure.

Smoking is never good for your blood pressure readings, especially right before a doctor’s appointment. “Smoking can raise your reading because it causes spasms of the arteries,” says Dr. Goldberg.

Your dinner the night before

“Eating a salty meal the day or night before can temporarily lead to an elevated reading,” says Dr. Goldberg. You should also be mindful of what you eat on the day of the exam; stick to a healthy, balanced diet with plenty of whole grains, lean protein, and fruits and veggies. Trying to reduce the amount of sodium in your diet is always a healthy move.

The blood pressure cuff

When it comes to the cuff, you are Goldilocks and it has to fit just right. If it’s too loose, you could get falsely low blood pressure readings; if it’s too tight, your reading might be inaccurately higher. “If the cuff feels too tight before it’s blown up, you know it’s too tight. If it’s falling off, you know it’s too big,” says Dr. Goldberg.

Your commute

A stressful trip to the doctor can throw your blood pressure reading way off once you actually get there. If traffic or crowded subways got your heart racing, ask to rest for five minutes before handing over your arm. “I usually let my patients rest for a few minutes so they can get their blood pressure to a more normal level. My assistant even shuts off the light,” Dr. Goldberg says.

How hydrated you are

Dehydration can lower your blood pressure readings, so be sure to drink plenty of fluids the day before and day of (and every other day, too). “It’s important we get an accurate assessment so we aren’t over-treating or under-treating people,” says Dr. Goldberg.

Your small talk

Don’t be rude, but if the person taking your blood pressure tries to make small talk, politely ask them to wait until after the reading. “Talking can raise your blood pressure, so just chill out,” says Dr. Goldberg.